#include <stdio.h>
unsigned int Gcd(unsigned int a,unsigned int b)
{
    unsigned int min,max,gcd;
    int i;
    max=a>=b?a:b;
    min=a<=b?a:b;//to find the more small number
    for(i=0;i<min;i++)
    {
        gcd=min-i;
        if(0==min%gcd&&0==max%gcd)
        {
            return gcd;
        }
    }
}
void main()
{
    unsigned int a,b;
    printf("Input two numbers:");
    scanf("%u,%u",&a,&b);
    printf("the greatest common divisor is %u",Gcd(a,b));
}
